infinibad: weird APIs switched to ->write_iter()

	Things Not To Do When Writing A Driver, part 1001st:
have writev() and write() on the same file doing completely
different things.  As in, "interpret very different sets of
commands".

	We _can_ handle that, but it's a bloody bad idea.
Don't do that in new drivers.  Ever.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index aed8afee56da..450d15965005 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -42,6 +42,7 @@
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/cpu.h>
+#include <linux/uio.h>
 #include <asm/pgtable.h>
 
 #include "ipath_kernel.h"
@@ -52,15 +53,19 @@ static int ipath_open(struct inode *, struct file *);
 static int ipath_close(struct inode *, struct file *);
 static ssize_t ipath_write(struct file *, const char __user *, size_t,
 			   loff_t *);
-static ssize_t ipath_writev(struct kiocb *, const struct iovec *,
-			    unsigned long , loff_t);
+static ssize_t ipath_write_iter(struct kiocb *, struct iov_iter *from);
 static unsigned int ipath_poll(struct file *, struct poll_table_struct *);
 static int ipath_mmap(struct file *, struct vm_area_struct *);
 
+/*
+ * This is really, really weird shit - write() and writev() here
+ * have completely unrelated semantics.  Sucky userland ABI,
+ * film at 11.
+ */
 static const struct file_operations ipath_file_ops = {
 	.owner = THIS_MODULE,
 	.write = ipath_write,
-	.aio_write = ipath_writev,
+	.write_iter = ipath_write_iter,
 	.open = ipath_open,
 	.release = ipath_close,
 	.poll = ipath_poll,
@@ -2413,18 +2418,17 @@ bail:
 	return ret;
 }
 
-static ssize_t ipath_writev(struct kiocb *iocb, const struct iovec *iov,
-			    unsigned long dim, loff_t off)
+static ssize_t ipath_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	struct file *filp = iocb->ki_filp;
 	struct ipath_filedata *fp = filp->private_data;
 	struct ipath_portdata *pd = port_fp(filp);
 	struct ipath_user_sdma_queue *pq = fp->pq;
 
-	if (!dim)
+	if (!iter_is_iovec(from) || !from->nr_segs)
 		return -EINVAL;
 
-	return ipath_user_sdma_writev(pd->port_dd, pq, iov, dim);
+	return ipath_user_sdma_writev(pd->port_dd, pq, from->iov, from->nr_segs);
 }
 
 static struct class *ipath_class;